1. Field of the Invention
The present invention relates to a method and apparatus for cleaning organic materials, and more particularly, to a method and apparatus for cleaning organic materials accumulated on a mask used in a process of depositing organic materials.
2. Description of the Related Art
Because organic light-emitting display devices exhibit a larger field of view, higher contrast, and a faster response rate than other display devices, organic light-emitting display devices have been receiving much attention as next-generation displays.
In general, organic light-emitting display devices have a stacked structure that includes two electrodes, i.e., an anode and a cathode, and an emission layer interposed between the anode and the cathode. Such organic light-emitting display devices display colors according to the principle in which holes and electrons respectively injected from the anode and the cathode recombine at the emission layer to emit light. However, because it may be difficult to achieve high light emission efficiency using this structure, intermediate layers such as an electron injection layer (EIL), an electron transport layer (ETL), a hole transport layer (HTL), and a hole injection layer (HIL) may be additionally interposed between the emission layer and each of the electrodes.
Manufacturing organic light-emitting display devices often includes forming an organic thin film, such as an emission layer and an intermediate layer, in a fine pattern by using a deposition method. The deposition method includes placing a mask having the same pattern as a thin film to be formed in close contact with a surface of a substrate on which an organic thin film is to be formed, and depositing a thin film material on the substrate through the mask to form the thin film having the desired pattern.
Within a deposition chamber used to deposit the finely patterned organic thin film, devices that include the mask are subjected to preventive maintenance (PM) on a regular cycle when the deposition process is repeatedly performed. In a process of manufacturing organic light-emitting display devices using a fine metal mask (FMM), the FMM may be separated for cleaning according to a predetermined PM cycle (e. g., after every 80 depositions on the substrate).
Information disclosed in this Background section was already known to the inventors before achieving the example embodiments or is technical information acquired in the process of achieving the example embodiments. Therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.